As is known, various types of structures to support vines, which are normally arranged in rows and suitably spaced apart, have been produced to form training supports, especially in the field of vine growing.
The structures of the supports essentially comprise rows of suitable posts set vertically in the ground and suitably spaced in line with each other, the parts that project above the soil being interconnected by a number of horizontal wires to support the shoots which attach themselves or are attached thereto in various ways by various means.
The arrangement of such structures has progressively evolved giving rise to a variety of configurations which clearly depend on a number of factors such as the type of vine or other fruit which it is desired to grow, the manual and mechanized operations which it is intended to carry out, etc.
The materials used have also progressively evolved, and in fact the posts, which were initially obtained from suitable pieces of wood, have now been almost entirely replaced by cement or metal components having cross-sections of various shapes often comprising suitable members for the attachment of horizontal wires. Also the wires which are stretched between the aforesaid posts, which, as is well known, used to comprise zinc-coated iron wires, have been replaced by stainless steel wires or metal wires obtained using special technologies.
In the arrangement, which is currently the most widespread in the field of vine growing, the support structure always comprises a plurality of equally spaced posts in line with each other, which are interconnected by a fixed horizontal wire known as the “supporting wire”, or also the “training wire”, which is fixed to the posts at a suitable height above the surface of the ground. At least one pair of wires, which are parallel to each other and positioned on corresponding sides of the supporting structure in question, and which in the specific field are commonly referred to as “containment wires” or also “moving wires” because, as is known, they are positioned at various heights above the ground during the various stages of cultivation, which take place throughout the year, are also attached to two posts located at the ends of each row. Initially these “moving wires” were fixed at least one of their ends to a corresponding post at a corresponding end of the corresponding row using attachment members provided with a suitable hooking member or suitable clamps referred to as “wire clamps”.
As a result, in order to carry out each individual movement, they first had to be slackened off, and then, when slackened off, positioned where necessary and finally retensioned. This procedure is complex and tiresome, requiring the employment of at least two persons and substantial working times, with consequent costs which are obviously appreciable.
In order to overcome these disadvantages and simplify the whole procedure, it has recently been the practice to place a helical spring working under tension between at least one of the ends of the “moving wires” and the corresponding ‘post to which that end is fixed. However, this arrangement in turn brings about not insubstantial disadvantages, because the maximum strength of the tension spring used must, for obvious reasons, be substantially less than that used when handling the moving wire. A result, when high random loads act even for very short periods, such as those caused by the thrust of the wind (“sail’ effect) or the action of mechanical operations or those deriving from random impacts caused involuntarily through the incorrect maneuvering of various machines {tractors-weeders, mechanical harvesters, etc.), among others, the aforesaid spring is overstretched, and being therefore permanently deformed has to be replaced. Given the random nature of the causes which might produce permanent damage to the spring, the necessary replacements of the same are obviously virtually unquantifiable and in any event numerous, as a result of which, the consequent costs for maintaining an efficient supporting structure are also unquantifiable, but obviously always high.